Traumatic Heterotopic Ossification Treatment & Management

Updated: Oct 30, 2019
  • Author: John B Wood, MBBS, FRCS(Edin), FRCS(Tr&Orth), FEBOT, Dip Sports Med (UNSW); Chief Editor: Harris Gellman, MD  more...
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Treatment

Surgical Therapy

Heterotopic ossification (HO) is seldom excised, because pain relief is often inadequate and improvement in range of motion (ROM) may not last. In established cases of HO following total hip arthroplasty (THA), excision may be performed. [11] The results of this procedure are varied. Patients may find that ROM improves, but pain relief is likely to be limited.

After trauma to the elbow, surgical excision may be indicated on the basis of pain, nerve entrapment, and stiffness. In such cases, the surgical procedure may be beneficial in that associated contractures are released, and this release can be as important as removal of the HO. [12] The timing of surgery is controversial. HO is often thought to take approximately 12 months to mature; however, surgical treatment of posttraumatic HO at the elbow has been performed effectively at 3 and 6 months post trauma. [13, 14]

The pearls for surgical treatment of HO are as follows:

  • Handle tissue carefully
  • Avoid excess bleeding
  • Achieve good hemostasis
  • Beware of lesions that span internervous tissue planes

Because removal of HO may involve substantial blood loss and excision may be incomplete, and because the risks of recurrence are high, surgeons attempting surgical removal of HO need to be familiar with the relevant surgical approaches to the affected region and to know how to enlarge and extend the wounds safely.

A definitive list of surgical contraindications for surgical excision of HO has not been established. However, excision should not be performed before the HO has matured, because incomplete and inadequate excision may result. Surgery on a joint that has wound sepsis or deep sepsis is contraindicated because the outcome is likely to be suboptimal.

Because the outcome of surgery is unpredictable, the indications must be considered carefully. Pain relief cannot be predicted reliably after excision of HO as a complication of THA, whereas better results for improved ROM arcs are more likely.

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Activity

Depending on where the ROM in the joints is impaired following arthroplasty as a result of HO, outpatient rehabilitation physiotherapy and hydrotherapy may be useful. The nature of the physiotherapy used for treatment is controversial. Forceful manipulation can be detrimental because the trauma involved can increase the development of HO. Physiotherapy that involves passive and active elements to maintain and increase ROM in the affected joints can be beneficial.

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Prevention

Traumatic HO can be treated in a number of ways. In the case of iatrogenic surgical trauma, prevention of the formation of HO should be considered the index treatment.

Modification of risk factors

A number of risk factors can be considered important in the pathogenesis of types of acquired HO:

  • Trauma
  • Burns
  • Neurologic injury
  • Previous HO
  • Previous resection of HO
  • Hip and pelvic surgery
  • Previous hip surgery sepsis
  • Revision surgery
  • Reoperation upon an existing arthroplasty
  • Reimplantation following an excision arthroplasty
  • Male sex
  • Advanced age (>60 years)
  • Genetic predisposition (possible)

Furthermore, patients who have conditions such as diffuse idiopathic skeletal hyperostosis, Paget disease, a preexisting hip fusion, posttraumatic arthrosis, hypertrophic osteoarthritis, or ankylosing spondylitis may be more likely to develop HO as a complication of THA. Children with cerebral palsy who undergo hip soft-tissue releases or spinal surgery are thought to have an increased risk of developing HO.

Risk factors that are related to surgical technique and therefore are potentially modifiable are as follows:

  • Prolonged surgery
  • Presence of pressure sores near the surgical field
  • Amount of bone resected
  • Amount of soft tissue dissected
  • Muscle ischemia
  • Tissue trauma
  • Bone trauma
  • Persistence of bone debris (reamings, marrow, or dust within the surgical field)
  • Prolonged soft-tissue retraction
  • Presence of devitalized tissue
  • Presence of hematoma
  • Postoperative wound infection
  • Prolonged postoperative wound drainage

Some case series have shown that factors such as the lateral approach to the hip, the use of cementless components, and the use of a trochanteric osteotomy may increase the risk of HO in THA, but these factors for increased risk are by no means certain. A meta-analysis by Zhu et al identified the following as risk factors for HO after THA [15] :

  • Male gender
  • Cemented implant
  • Bilateral operations
  • Ankylosing spondylitis
  • Ankylosed hip

A patient with HO following THA is thought to have a 90-100% chance of developing it on the contralateral hip if this hip also undergoes THA. Consequently, certain patients with preexisting risk factors could conceivably be regarded as high-risk and be treated with a more intensive prophylaxis regimen than the standard one, though this may not be practical. Nevertheless, it would be prudent to minimize the risk of HO developing after arthroplasty by performing surgery whereby the following are ensured:

  • Exposure is meticulous
  • Retraction is performed carefully and soft tissue is handled carefully
  • Irrigation is adequate
  • Devitalized tissue is excised
  • Hemostasis is adequate
  • Postoperative drains (when used) are not retained for longer than necessary
  • Perioperative antibiotic prophylaxis is used
  • Postoperative anticoagulation (when used for deep vein thrombosis prophylaxis) is carefully controlled

A systematic review of 45 studies by Liu et al, which included 2256 patients who underwent total elbow arthroplasty (TEA), found that the literature did not support routine HO prophylaxis for TEA and noted that the effectiveness of prophylaxis in high-risk patients was uncertain and in need of clarification. [16]

Pharmacologic prophylaxis and localized radiotherapy

After procedures that may be complicated by HO, recommendations indicate that prophylaxis should be given in the form of nonsteroidal anti-inflammatory drugs (NSAIDs), such as indomethacin, or aspirinlike drugs that act as nonspecific cyclooxygenase (COX) inhibitors. [17, 18] The duration of treatment is controversial. Some studies have shown that treatment should continue for 6 weeks after the procedure; others have suggested that it need only be continued for 20, 14, or 7 days after the procedure. Bisphosphonates are ineffective in the prophylaxis of HO.

An alternative or possible adjunct to COX inhibition is the use of localized irradiation. [19] However, clinical evidence suggests that localized irradiation is not better than indomethacin alone for HO prophylaxis following surgery of acetabular fractures. Some clinicians would advocate the use of adjuvant radiation therapy in the prophylaxis of HO in individuals considered to be at high risk (defined as a ≥50% chance) for this condition.

The irradiation protocol is controversial. Radiation therapy may be effective if given up to 24 hours preoperatively or within 72 hours postoperatively. However, it is unclear whether an optimal time to apply the treatment dose exists within these differing schedules. Randomized trials have shown that single fractions are as effective as multifraction schedules. Debate exists regarding the irradiation dosage. Some studies indicate that 7 Gy may be more effective than 5.5 Gy as a single dose; others recommend 8 Gy or 12 Gy doses as single fractions or multifraction regimens.

The role of radiation therapy in HO prophylaxis is not fully defined, and because its logistic availability is limited, its use will continue to be selective rather than widespread.

Pakos et al evaluated the efficacy of combined radiotherapy and indomethacin against that of indomethacin alone for prevention of HO after hip arthroplasty in 96 patients, who received either a single dose of postoperative radiotherapy of 7.0 Gy and indomethacin for the first 15 postoperative days or indomethacin alone for the same period. [20] A historical group of 50 patients who received indomethacin alone served as the control group.

In this study, four patients in the combined-therapy group developed HO, compared with 13 patients in the indomethacin group and 13 in the control group. [20] One patient in the combined-therapy group and one in the control group developed Brooker III HO. Duration of surgery and congenital hip disease were associated with HO development in the indomethacin groups; in the combined-therapy group, age and congenital hip disease were associated with HO.

Prophylaxis using NSAIDs may be complicated by the adverse effects of these drugs. Radiation therapy complications may also occur if this approach is used for prophylaxis. However, the exact incidence of these complications is not known. Long-term follow-up studies to detect late complications are lacking. A case-control analysis by Sheybani did not demonstrate any increase in the risk of radiation-induced malignancy in patients who received radiation therapy as prophylaxis for HO. [21]

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